MacBook4.1 early 2008 - Upgrade Ram and Storage

Question

Hey Guys, my English is not good, so please, take me patient = )
I have a Black MacBook early 2008, ( MacBook4,1 ). I want to do a Ram and HD upgrade.
I was reading
https://discussions.apple.com/thread/3226716?start=0&tstart=0
but i am not sure if i can upgrade to 8gb in Lion, and wich Hard Disk is good for me.
Any way, I am thinking whats the better option: Do a Upgrade or buy a new MacBook.
I know, i cant upgrade for 10.8 or 10.9 but i want to know if i can use this machine for a ltlle more of time.,
Please,  tell me, in your opinion, whats the better option.
If you can, please, indicate how can i upgrade 4, 6, or 8GB acording your suggest. I am not sure
if i can put 8G Ram in the machine. (btw, that will be amazing)
For HD i have no idea for compatibles disks with this model, (size, etc)
My intension is use this apps: Autocad, Win8 with bootcamp, Photoshop, Office, etc...
I''ll be happy paying until 400$ for Upgrades.
I was reading for problems with 8gb in macbooks 4,1, but i dont know...
Thanks anyway!
Spec sys:
Hardware Overview:
  Model Name:          MacBook
  Model Identifier:          MacBook4,1
  Processor Name:          Intel Core 2 Duo
  Processor Speed:          2,4 GHz
  Number of Processors:          1
  Total Number of Cores:          2
  L2 Cache:          3 MB
  Memory:          2 GB
  Bus Speed:          800 MHz
  Boot ROM Version:          MB41.00C1.B00
  SMC Version (system):          1.31f1
  Serial Number (system):          W8******0P2
  Hardware UUID:          0A4651CF-CFA4-5824-8223-0D7EFF41F550
  Sudden Motion Sensor:
  State:          Enabled
Ethernet:
  Type:          Ethernet
  Hardware:          Ethernet
  BSD Device Name:          en0
  IPv4:
  Configuration Method:          DHCP
  IPv6:
  Configuration Method:          Automatic
  Ethernet:
  MAC Address:          00:22:41:2f:fb:e9
  Media Options:
  Media Subtype:          Auto Select
  Proxies:
  Exceptions List:          *.local, 169.254/16
  FTP Passive Mode:          Yes
  Service Order:          0
System Software Overview:
  System Version:          Mac OS X 10.7.5 (11G63)
  Kernel Version:          Darwin 11.4.2
  Boot Volume:          Odin
  Boot Mode:          Normal
  Computer Name:          Hernan’s MacBook
  User Name:          Hernan Rosas (hernan)
  Secure Virtual Memory:          Enabled
  64-bit Kernel and Extensions:          No
  Time since boot:          17 minutes
<Edited by Host>

Answer 1

The model 4,1 (Early 2008) can use 6gb of 200 pin 667mhz PC2-5300 RAM
These are good online stores for Mac compatible RAM
OWC 667Mhz RAM
http://eshop.macsales.com/shop/memory/MacBook/DDR2/ - They offer Mac tested RAM at very good prices.
Crucial Memory http://www.crucial.com/ - good place to buy RAM from all over the world. They also have an excellent memory selector that allows you to choose memory based on your computer's model
Data Memory Systems http://www.datamemorysystems.com/apple-memory.asp - another good, cheap place to buying RAM if you live in the U.S.
Here are instructions on replacing RAM in a MacBook with a removable battery. http://homeoffice.consumerelectronicsnet.com/articles/viewarticle.jsp?id=44404
If you don’t have the tools to open up the MacBook OWC has a set for $5.
http://eshop.macsales.com/item/OWC/TOOLKITMHD/